Device for removing piston rods from cross heads



Jan. 11, 1938. x ANDERSON 2,105,392

DEVICE FOR REMOVING PISTON RODS FROM CROSS HEADS Filed Aug. 12, 1936 BY myzmlfll ATTORN EYS Patented Jan. 11, 1938 SNETED STATES P T FFIE DEVHCE FOR REMOVING PISTON RODS 1 Claim.

My invention relatesto improvements in devices for removing piston rods from cross heads.

The removal of piston rods from cross heads of locomotives is attended with considerable difiiculty and danger because of the fact that these parts frequently become frozen together. The separa tion of such parts, under these conditions, particularly while on the locomotive, requires the application of a powerful force and frequently, with the type of apparatus now in use, cannot be accomplished at all, at least not without resorting to heating of the parts, which is objectionable for reasons well understood. Devices for this purpose, known to me, are designed to drive the piston rod out of the cross head under the action of hammer blows but are practically useless when the piston rod is frozen for the reason that they are inefiicient as regards the application of the force required to drive the piston out under these circumstances. Moreover, they invariably embody punch devices for operation against the cross head end of the piston rod and which, under the hammer blows, shift out of alignment with the piston rod and thereby become partially inefiective, or score or upset the cross head end of the piston rod against which they are positioned.

Having the foregoing in mind, my invention is designed primarily to provide an assembly of few parts for driving the piston rod and cross head apart using the wrist pin openings as a fixed point, and adapted to direct, under comparatively light hammer blows, a force against the cross head end of the piston rod suficient to dislodge the same when frozen in the cross head, the assembly comprising cooperating parts disposed between said openings and the cross head end of the piston rod, which are self-aligning under the hammer blows, with the axis of the rod so as to direct the driving force thereagainst in a manner such that said end of the rod will not be scored or upset.

Other objects are to provide devices of the character and for the purpose set forth which are strong and durable, readily assembled and disassembled, and comparatively inexpensive to manufaoture.

To the accomplishment of the above and subordinate objects presently appearing, a preferred embodiment of my invention has been illustrated in the accompanying drawing and described and defined in the following description and claim, respectively.

In said drawing:

Figure 1 is a View in top plan illustrating the application of my invention to a cross head and piston rod,

Figure 2 is a view in transverse section taken on the line 2-2 of Figure 1 looking in the direction indicated by the arrows,

Figure 3 is a perspective view of a punch member forming part of the assembly,

Figure 4 is a similar view of a compensating block forming part of the punch member, and

Figure 5 is a view in perspective of an insert presently described in detail.

Referring to the drawing in detail, it will be noted that the piston rod and cross head have been illustrated conventionally therein by dotted lines, and the piston rod which is indicated by the reference numeral l is provided with the usual tapered cross head receiving end 2 which is mounted in the cross head 3, the latter having side flanges 4 and a bottom flange 5. The usual wrist pin openings in the cross head flanges 4 are indicated by the numeral 6.

It will be obvious that the above described structure is for the purpose of illustration only and my invention includes what may be termed an insert block or pin 1 which is cylindrical in form and slightly tapered toward one end, so as to fit into the wrist pin openings 6. The insert block has formed longitudinally in one side thereof an open guide slot 8 that extends inwardly substantially to the axis of the insert block and is of rectangular form transversely. The slot 8 is designed to act as a guide for a wedge or tapered key 8 of substantially less width than the slot and slidably fits therein, as indicated in Figure 1.

My device likewise includes a punch member 9 that is to be interposed between the wedge or key 8 and the piston rod I and is provided with a cylindrical shank l0 having a driving or outer end of slightly smaller diameter than that of the cross head end of the piston rod l. The opposite end of the shank l6 has formed thereon a flat head part ii that is provided with outwardly flared side portions I2 and straight side portions l3, the latter being adapted to fit loosely between the flanges 4 of the cross head, as shown in Figure 1.

The outer end of the head part II is provided with a semi-circular socket l4 therein having flat parallel upper and lower walls l5 and I6 respectively, and which has mounted therein a semicircular part I! of a compensating block l8, the latter having a flat outer face IQ for a purpose which will be later described. The semi-circular part I! of the block i8 is pivotally secured in the socket l4 through the instrumentality of a pivot pin 20, and the block l-S is of proper width and thickness to fit between the flanges 4 and into the guide slot 8 for sliding movement therein.

The punch member 9 including the compensating block which is pivotally secured thereto is designed to fit approximately between wedges of difierent widths and the cross head end' of the piston rod I, and a filler plate retainer 2| of cap like form to receive one or more filler plates or shims 22, may be interposed between the shank I and the piston rod l, as best shown in Figure 2. The outer end of the shank l 0 is centered relative to the piston rod l by means of a support or rest 23 in the form of a flat block of wood or the like, and which is disposed upon the flange of the cross head, with a concaved seat 24 therein to receive the shank. The remaining parts of the device are preferably formed from steel.

it will be noted from Figure 2 that the shank I0 is provided with a centrally disposed threaded bore 25 extending therein and the plate 22 as well as the retainer 2| is provided with openings to register with the bore, and the purpose of the bore and openings is to receive a screw bolt, not shown, for holding the retainer and plates fixed to the shank, when the device is not in use, so as to prevent loss thereof.

In assembling the parts of the device for use, the support 23 is first placed in and against the rear wall of the cross head, as clearly shown in Figure 2, then the insert block or pin 6 is disposed into the wrist pin openings 6, in a manner whereby the slot 8 thereof is preferably disposed rearwardly with respect to the cross head. The compensating block H which is pivotally secured to the head part II of the punch head 9 is placed in the guide slot 8, then the parts are rotated or tLu'ned over until the outer end of the shank H! is disposed in the seat 24, or in position for use. The Wedge or key 8 is driven into the guide slot for disposal between the flat face I9 and the inner wall of the slot, and it will be obvious that the driving action of the wedge will gradually force the piston rod I from the bore of the cross head, which can be accomplished by my device with minimum time and effort without heating the cross head which is found necessary in the use of similar devices of this character.

By having the compensating block I! pivotally mounted with respect to the head part I! different styles or types of wedges may be used, and in this connection, it is to be noted that the semicircular walls of the block I! and the socket M are adapted for co-engagement to take the driving strains off of the pivot pin 29. The block I! is likewise of proper width to provide a slight clearance between the same, and the flanges 4, to

permit compensating movement of the block, as will be apparent.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction and in the combination and arrangement of the several parts, provided that ing movement therein, said compensating block .5

having a flat outer face and received in the slot of the cylindrical block, a wedge shaped key to be driven in the slot for engagement with the fiat outer face, a plurality of shims to be positioned between the driving end of the shank and the rod, a retaining cap for the shims and fitting the driving end and means for securing the retaining cap to the driving end.

HARRY A. ANDERSON. 

